Bottom currents, submarine mass failures and halokinesis at the toe of the Sigsbee Escarpment (Gulf of Mexico)

Contrasting regimes during lowstand and highstand conditions?

V. Maselli, B. Kneller

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Abstract

Abstract In this study we explore the role of sediment supply, halokinesis and deep ocean circulation in promoting margin instability. The analysis was carried out on multibeam and high-resolution seismic data that allowed the imaging of mass failure deposits and current-driven depositional features along a portion of the lower continental slope and upper continental rise of the Sigsbee Escarpment (Gulf of Mexico). Different styles of deposition have been recognised during sea level lowstand (LST) and highstand (HST) conditions, due to alternating bottom current activity and salt tectonics. Lowstands are characterized by a reduced intensity of the Loop Current, as underlined by the lack of current-driven erosional features. On the contrary, highstands show a strengthened Loop Current that generates a fast bottom current circulation, as suggested by the presence of extensive furrow fields on the modern sea floor and on the Marine Isotope Stage 5e palaeo-sea floor horizon. Increased sediment load combined with changes in the intensity of deep water circulation are also responsible for the instability of the Sigsbee Escarpment, triggering mass failure phenomena with distinct morphology, size, location and timing of emplacement. Type 1 mass transport complexes (MTCs) form on the upper continental rise during sea level fall, and are genetically linked to the growth of deep water sediment drifts. Type 2 MTCs develop during sea level lowstands and originate along the slope of the Sigsbee Escarpment, triggered by oversteepening generated by halokinesis. Type 3 MTCs form during sea level rise to highstand conditions and mostly consist of debris flow deposits, generated in the lower portions of the Sigsbee Escarpment and then accumulated in the upper continental rise.
Original languageEnglish
Pages (from-to)36-65
Number of pages30
JournalMarine Geology
Volume401
Early online date3 Apr 2018
DOIs
Publication statusPublished - 1 Jul 2018

Fingerprint

bottom current
Sea level
lowstand
escarpment
highstand
continental rise
mass transport
Sediments
Mass transfer
sea level
Salt tectonics
seafloor
Deposits
deep water
sediment
salt tectonics
marine isotope stage
Water
continental slope
Debris

Keywords

  • Mass transport complex
  • Sediment drift
  • Hazard
  • Seismic geomorphology
  • Gulf of Mexico

Cite this

@article{52bfa26c2d264c9394576c082134c087,
title = "Bottom currents, submarine mass failures and halokinesis at the toe of the Sigsbee Escarpment (Gulf of Mexico): Contrasting regimes during lowstand and highstand conditions?",
abstract = "Abstract In this study we explore the role of sediment supply, halokinesis and deep ocean circulation in promoting margin instability. The analysis was carried out on multibeam and high-resolution seismic data that allowed the imaging of mass failure deposits and current-driven depositional features along a portion of the lower continental slope and upper continental rise of the Sigsbee Escarpment (Gulf of Mexico). Different styles of deposition have been recognised during sea level lowstand (LST) and highstand (HST) conditions, due to alternating bottom current activity and salt tectonics. Lowstands are characterized by a reduced intensity of the Loop Current, as underlined by the lack of current-driven erosional features. On the contrary, highstands show a strengthened Loop Current that generates a fast bottom current circulation, as suggested by the presence of extensive furrow fields on the modern sea floor and on the Marine Isotope Stage 5e palaeo-sea floor horizon. Increased sediment load combined with changes in the intensity of deep water circulation are also responsible for the instability of the Sigsbee Escarpment, triggering mass failure phenomena with distinct morphology, size, location and timing of emplacement. Type 1 mass transport complexes (MTCs) form on the upper continental rise during sea level fall, and are genetically linked to the growth of deep water sediment drifts. Type 2 MTCs develop during sea level lowstands and originate along the slope of the Sigsbee Escarpment, triggered by oversteepening generated by halokinesis. Type 3 MTCs form during sea level rise to highstand conditions and mostly consist of debris flow deposits, generated in the lower portions of the Sigsbee Escarpment and then accumulated in the upper continental rise.",
keywords = "Mass transport complex, Sediment drift, Hazard, Seismic geomorphology, Gulf of Mexico",
author = "V. Maselli and B. Kneller",
note = "We are grateful to BP for the provision of both sea-floor and subsurface data. We thank the journal editor Michele Rebesco for his continuous support, and Lorena Moscardelli, Daniele Casalbore and an anonymous reviewer for their detailed and constructive comments, which have allowed us to considerably improve the manuscript.",
year = "2018",
month = "7",
day = "1",
doi = "10.1016/j.margeo.2018.04.001",
language = "English",
volume = "401",
pages = "36--65",
journal = "Marine Geology",
issn = "0025-3227",
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TY - JOUR

T1 - Bottom currents, submarine mass failures and halokinesis at the toe of the Sigsbee Escarpment (Gulf of Mexico)

T2 - Contrasting regimes during lowstand and highstand conditions?

AU - Maselli, V.

AU - Kneller, B.

N1 - We are grateful to BP for the provision of both sea-floor and subsurface data. We thank the journal editor Michele Rebesco for his continuous support, and Lorena Moscardelli, Daniele Casalbore and an anonymous reviewer for their detailed and constructive comments, which have allowed us to considerably improve the manuscript.

PY - 2018/7/1

Y1 - 2018/7/1

N2 - Abstract In this study we explore the role of sediment supply, halokinesis and deep ocean circulation in promoting margin instability. The analysis was carried out on multibeam and high-resolution seismic data that allowed the imaging of mass failure deposits and current-driven depositional features along a portion of the lower continental slope and upper continental rise of the Sigsbee Escarpment (Gulf of Mexico). Different styles of deposition have been recognised during sea level lowstand (LST) and highstand (HST) conditions, due to alternating bottom current activity and salt tectonics. Lowstands are characterized by a reduced intensity of the Loop Current, as underlined by the lack of current-driven erosional features. On the contrary, highstands show a strengthened Loop Current that generates a fast bottom current circulation, as suggested by the presence of extensive furrow fields on the modern sea floor and on the Marine Isotope Stage 5e palaeo-sea floor horizon. Increased sediment load combined with changes in the intensity of deep water circulation are also responsible for the instability of the Sigsbee Escarpment, triggering mass failure phenomena with distinct morphology, size, location and timing of emplacement. Type 1 mass transport complexes (MTCs) form on the upper continental rise during sea level fall, and are genetically linked to the growth of deep water sediment drifts. Type 2 MTCs develop during sea level lowstands and originate along the slope of the Sigsbee Escarpment, triggered by oversteepening generated by halokinesis. Type 3 MTCs form during sea level rise to highstand conditions and mostly consist of debris flow deposits, generated in the lower portions of the Sigsbee Escarpment and then accumulated in the upper continental rise.

AB - Abstract In this study we explore the role of sediment supply, halokinesis and deep ocean circulation in promoting margin instability. The analysis was carried out on multibeam and high-resolution seismic data that allowed the imaging of mass failure deposits and current-driven depositional features along a portion of the lower continental slope and upper continental rise of the Sigsbee Escarpment (Gulf of Mexico). Different styles of deposition have been recognised during sea level lowstand (LST) and highstand (HST) conditions, due to alternating bottom current activity and salt tectonics. Lowstands are characterized by a reduced intensity of the Loop Current, as underlined by the lack of current-driven erosional features. On the contrary, highstands show a strengthened Loop Current that generates a fast bottom current circulation, as suggested by the presence of extensive furrow fields on the modern sea floor and on the Marine Isotope Stage 5e palaeo-sea floor horizon. Increased sediment load combined with changes in the intensity of deep water circulation are also responsible for the instability of the Sigsbee Escarpment, triggering mass failure phenomena with distinct morphology, size, location and timing of emplacement. Type 1 mass transport complexes (MTCs) form on the upper continental rise during sea level fall, and are genetically linked to the growth of deep water sediment drifts. Type 2 MTCs develop during sea level lowstands and originate along the slope of the Sigsbee Escarpment, triggered by oversteepening generated by halokinesis. Type 3 MTCs form during sea level rise to highstand conditions and mostly consist of debris flow deposits, generated in the lower portions of the Sigsbee Escarpment and then accumulated in the upper continental rise.

KW - Mass transport complex

KW - Sediment drift

KW - Hazard

KW - Seismic geomorphology

KW - Gulf of Mexico

U2 - 10.1016/j.margeo.2018.04.001

DO - 10.1016/j.margeo.2018.04.001

M3 - Article

VL - 401

SP - 36

EP - 65

JO - Marine Geology

JF - Marine Geology

SN - 0025-3227

ER -